Propeller for motor boats



April 9, 1929. TOLSTQN 1,708,489

PROPELLER FOR MOTOR BOATS Filed March 15. 1926 gwwntoz,

Z/ZYaZrZa Patented Apr. 9, 1929.

ELBERT MONROE 'IOLSTON, OF MACON, GEORGIA.

PROPELLER non MOTOR BOATS.

Application filed March 15, 1926.

This invention relates to a propeller for motor boats.

It is aimed to provide a novel, simple and inexpensive construction andparticularly one having blades operable on one stroke and inactive onthe other stroke and adapted for operation through reciprocatingmechanism.

The more specific objects and advantages will become apparent from aconsideration of the description following taken in conneetion with theaccompanying drawings illustrating one embodiment.

In said drawings Figure 1 is a view illustrating the invention in sideelevation and in connection with a boat, the latter being fragmentarilyillustrated;

Figure 2 is a plan view of the parts of Figure 1;

Figure 3 is a detail sectional view taken on line 33 of Figure 2; and,

Figure at is a detail plan View showing the blades retracted in fulllines and the blades in the position they assume while on theirinoperative stroke. .i

Referring specifically to the drawing, 10 designates a conventional boator vessel adapted to carry a suit-able prime mover such as an oil orgasoline engine or a steam engine, (not necessary to illustrate), andwhich drives a shaft 11 shown as mounted in a bearing- 12 within theboat. Shaft 11 has a bevel gear wheel 13 keyed thereto which meshes witha bevel gear wheel 14 rigid with a drive wheel 15 of a larger diameterthan the same as by means of a stub shaft 14 journalled in a bearingplate 14 fastened to the rails or sides of the boat as at 14 orotherwise. Connected to the wheel 15 by a wrist pin 16 is a pitinan 17which is pivoted at 13 to a reciprocatory bar 19 slidably guided througha hearing or waterproof stuffing box 20 fastenedat the stern of thevessel or boat 10.

Bar '19 extends outwardly of the boat beyond the stern and at its rearend is vertically enlarged into a block 21. On the block 21, through themedium o.L overlapping Serial No. 94,836.

cars 22 and a fastening 24 are two curved propeller blades 23. The earspivot on fastening 24: and the same located closer to one end of theblades 23 than the other end, thus having relatively large main'iortions 25 and relatively short abutment portions 26, the portions 26being adapted for abutment against bar 19 in the open position of theblades as shown in dotted lines in Figure In operation, as shaft 11rotates, gear wheels 13 and let drive wheel 15, and thus reciprocatepitman 17 and bar 19. As the lades 23 move with the bar 19 toward thestern of the boat, they are in the position shown in full lines inFigures 3 and a, due to the impingement of the water against the outersurfaces of the portion 25, thus form ing, as shown in said figures, arelatively thin body offering minimum resistance to the water. Vfhen thebar 19 moves the blades 23 away from the stern of the boat, the main orinner surfaces of portions 25 impinge against the water, thus engagingthe same to the maximum extent as suggested by the dotted lines of Fignre 4:, accordingly offerin resistance to the blades so that theeffect thereof is imparted to the boat to propel the same, The openingof the blades 23 to the propelling position is limited by the engagementof the portions 26 with the bar 19 in dotted lines in Figure 4.

Various changes may be resorted to provided they fall within the spiritand scope of'the invention.

I claim:

A propelling mechanism comprising a reciprocatory bar, co-actinpropeller blades, said blades being on substantially the same curvethroughout their length and having their convex surfaces facing eachother, means pivoting said blades closer to their inner ends than totheir outer ends and to said bar, the said blades being adapted tocontact at their convex surfaces with the bar intermediate their pivotand the inner ends of the bars.

In testimony whereof I atlix my signature.

ELBERT MONROE TOLSTON.

